package FirstChapter.one;

/**
 * Created by Lee on 2017/2/14 0014.
 */
public class Seven {
    public static void main(String[] args) {
        double t = 9.0;
        while(Math.abs(t- 9.0/t)>.001){
            t=(9.0/t+t)/2.0;
        }
        System.out.println(t/9.0);
    }
}
